Generation of Adenovirus Vectors Devoid of All Viral Genes by Recombination Between Inverted Repeats

Adenovirus (Ad) vector-mediated gene transfer is useful in applications where transient, high-level transgene expression is required. In contrast to onco-retroviral vectors, Ad vectors efficiently infect nondividing cells. Most recombinant Ad vectors currently used for in vitro and in vivo gene transfer are usually deleted for the E1 and/or E3 region (first-generation Ad vectors) and are based on serotype 5 (Ad5). First-generation Ad vectors can be produced and purified at high titers. Disadvantages of these gene transfer vehicles include their episomal nature that only allows for short-term gene expression, cytotoxicity from expressed viral proteins, and elicitation of immune responses. In order to circumvent these problems, new recombinant Ad vectors devoid of all viral genes have been developed (1 ). These “gutless” Ad (ΔAd) vectors show significantly less cytotoxic and immunogenic side effects.